It is known in the prior art to measure physiological parameters during training. United States application publication number 2006/0057549 A1 discloses training for attaining a physiological state consistent with the successful performance of a task, wherein the training takes place in the physical environment of the task in question (putting green, tennis court, lacrosse field, etc.) and the training comprises static repetition of the task in the presence of information related to the user's physiological state during iterations of the task.
United States application publication number US2009/0137915 A1, which does not disclose training, does disclose determining the state of overlap between biological systems which exhibit oscillatory behavior such as heart rhythms, respiration, blood pressure waves, low frequency brain waves, based on a determination of heart rate variability (HRV), and an evaluation of the power spectrum thereof.
In addition the following patent publications concern related subject matter: US20100022852A1, US20080214903A1, US20090105605A1, US20030009087A1, US20080171914A1, US20120116176A1, US20090082685A1, and US20110015468A1.